Conventionally, there has been known a wire bonding device that bonds an electrode of a semiconductor chip and a lead for wiring formed on a substrate with a wire.
A wire bonding device presses a ball formed at a leading end of a wire to an electrode of a semiconductor chip with ultrasonic vibration to bond the ball thereto and presses the wire to a lead with ultrasonic vibration, so that the electrode on the semiconductor chip and the lead on the substrate are bonded.
In a wire bonding device, a bonding head is fixed as being placed on an XY-table movable in two-dimensional directions. A bonding arm that constitutes the bonding head is configured to be rotatable about a support shaft. The bonding arm is provided at a leading end at one side with an ultrasonic horn to which a capillary serving as a bonding tool is attached and is provided at the other side with an ultrasonic transducer serving as an ultrasonic applying unit that applies ultrasonic vibration to the capillary via the ultrasonic horn.
Here, the ultrasonic horn of the conventional bonding arm is required to have a length on the basis of λ (acoustic wavelength)/2. Further, when the ultrasonic horn is attached to the bonding head serving as the bonding arm, the ultrasonic horn is fixed to a position at a node of λ/4. Thus, there have been restrictions for the length, the support method, and the like.
To eliminate such restrictions, Patent Document 1 discloses a wire bonding device in which a piezoelectric element that transmits vibration to a capillary with an electric strain effect or a magnetic strain effect is assembled to a bonding arm in the vicinity of a position where the capillary is attached.
Further, Patent Document 2 discloses a low mass transducer having a vibration generating mechanism assembled to a capillary.